surcoat
/ˈsɜːkəʊt/noun
1- historical a loose robe worn over armour〈史〉（穿在铠甲外的）铠甲罩袍。
1.1
- a similar sleeveless garment worn as part of the insignia of an order of knighthood（作为表明骑士级别标志的）无袖罩袍。
1.2
- an outer coat of rich material用贵重布料制成的外套。
词源
Middle English: from Old French surcot, from sur 'over' + cot 'coat'.